const fp = require('lodash/fp')

const cars = [
    {
        name: 'Ferrari FF', horsepower: 660, dollar_value: 700000, in_stock: true
    },
    {
        name: 'Spyker C12 Zagato', horsepower: 650, dollar_value: 648000, in_stock: false
    },
    {
        name: 'Jaguar XKR-S', horsepower: 550, dollar_value: 132000, in_stock: false
    },
    {
        name: 'Audi R8', horsepower: 525, dollar_value: 114200, in_stock: false
    },
    {
        name: 'Aston Martin One-77', horsepower: 750, dollar_value: 1850000, in_stock: true
    },
    {
        name: 'Pagani Huayra', horsepower: 700, dollar_value: 1300000, in_stock: false
    }
]

// 1. 重新实现isLastInStock
let isLastInStock = fp.flowRight(fp.prop('in_stock'), fp.last)

// 2. 获取第一项的名字
let getFirstName = fp.flowRight(fp.prop('name'), fp.first)
const name = getFirstName(cars)

// 3. 重构avreageDollarValue
let _average = function (xs) {
    return fp.reduce(fp.add, 0, xs) / xs.length
}
let avreageDollarValue = fp.flowRight(_average, fp.map(fp.prop('dollar_value')))

// 4. 实现 sanitizeNames
let _undescore = fp.replace(/\W+/g, '_')
const sanitizeNames = fp.map(fp.flowRight(_undescore, fp.toLower))


